Typical photoreceivers using either a voltage amplifier, a transimpedance amplifier or a phototransistor need to extract photo-generated current either using bias resistors or base current of the phototransistor, so that shot noises may be generated in addition to shot noises of photons themselves and may limit the ultimate sensitivity of the photoreceivers.
The bias current limitation may be circumvented using a switched (or clocked) photoreceiver, where the photo-generated charge may be drained away at a time when the system is insensitive to noise. The switched pohotoreceiver may be less noisy than other photoreceivers. However, the switching circuitry can be power consuming and synchronization with input data stream may be difficult. Thus, a photoreceiver design with less noisy and low power consumption is needed.